Guizhou Hillstream Loach (Beaufortia kweichowensis)

Species Overview (Beaufortia kweichowensis)

← Back to Loach (genus overview)

I. Basic Information

• Chinese Name: 贵州爬岩鳅

• Common Name: Guizhou Hillstream Loach

• Scientific Name: Beaufortia kweichowensis

• Family / Genus: Gastromyzontidae · Beaufortia

• Native Range: Mountain streams of Guizhou Province, China

• Adult Size: 6–7 cm

• Market Status:
  The most common and widely traded hillstream loach. Artificial breeding is stable. Three color forms are currently available: wild-type, red morph, and yellow morph.

II. Natural Habitat

• Inhabits clear mountain streams with moderate to strong current

• Substrate composed of smooth stones and slate, without mud or silt

• Water temperature: 16–24°C

• High dissolved oxygen and excellent water clarity

• Feeds exclusively on natural biofilm growing on rock surfaces

III. Morphological Characteristics

• Body cylindrical, anterior portion flattened ventrally, posterior slightly laterally compressed

• Base coloration grey-brown to dark brown, ventral side pale yellow

• Head and dorsal surface densely covered with fine, evenly distributed dark round spots, without transverse bands

• Pectoral and pelvic fins with distinct white outer margins and a sharp black inner line — the most stable diagnostic feature

• Dorsal and caudal fins marked with rows of black spots forming longitudinal patterns

• Adult males develop small keratinized tubercles on both sides of the snout

Color Variants

All forms lack blue fins, green patches, and transverse bands.

IV. Behavior and Temperament

• Remains attached to rock surfaces throughout the day, slowly grazing

• Slightly more active at dawn and dusk; mostly stationary during daytime

• Non-aggressive and highly tolerant of conspecifics when sufficient attachment surfaces are provided

• Locomotion is performed by “crawling” with the pectoral fins; rarely leaves the substrate

V. Feeding Ecology

• Specialized grazer of epilithic algae, including diatoms, green film algae, and brown biofilm

• In mature hillstream aquaria, continuous algal growth eliminates the need for supplemental feeding

• When biofilm is abundant, feeding is entirely unnecessary

• Refuses bloodworms, tubifex, pellets, and all high-protein animal-based foods

📌 This is not a fish that requires feeding — it is a functional algae grazer.

VI. Reproduction (Artificial Observations)

• Breeding season: April to July (22–25°C)

• Eggs are deposited on the underside of stones or in crevices and are adhesive

• Fry begin grazing microalgae immediately after yolk absorption

VII. Husbandry Difficulty

• Difficulty Rating: ★★★☆☆ (relatively easy among hillstream loaches)

Key Success Factors

• Water temperature ≤28°C (heat is the primary cause of mortality)

• Strong current and high dissolved oxygen

• Clean substrate without organic accumulation

Primary Causes of Failure

• High temperature

• Stagnant water

• Thick muddy substrate

• Improper feeding with high-protein diets

VIII. Aquarium Care Recommendations

1. Tank Size and Stocking Density

• 40 cm tank (30–40 L): 2–6 individuals

• 60 cm tank (60 L): up to 20 individuals

Condition: sufficient smooth rock surfaces for attachment and grazing.

2. Water Parameters and Flow

3. Aquascaping and Maintenance

• Substrate: fine river sand (1–2 mm), depth ≤2 cm

• Hardscape: abundant smooth stones, slate, or flagstone (primary grazing surfaces)

• Lighting: 8–10 hours daily (high light encourages natural algal growth)

• Filtration: hang-on filters, waterfall filters, or small circulation pumps recommended

• Maintenance: remove algae from glass and equipment, but preserve biofilm on stones — this is the feeding ground

💡 In a healthy hillstream aquarium, algae are not a problem but a resource — this species exists precisely for that purpose.

IX. Feeding Guidelines

• Under normal conditions, no feeding is required

• Temporary supplementation only in extreme situations:

  • Newly established tanks without established biofilm (a small piece of blanched spinach may be offered and removed within 3 days)

  • Rare cases of abnormal emaciation

Routine feeding is prohibited:
Any sinking food may pollute the substrate and cause serious health problems.

X. Tankmates and Conservation

Compatible Tankmates

• Peaceful mid–upper layer fish: White Cloud Mountain Minnow, Danio, small barbs

• Adult ornamental shrimp: Cherry shrimp, Fire shrimp

Incompatible Species

• Plecos and loricariids (competition and physical suppression)

• Aggressive fish (bettas, cichlids)

• High-density benthic species (competition for attachment surfaces)

Conservation Note

• Endemic species of China, subject to general wildlife protection

• Most market specimens are captive-bred; captive stock is strongly recommended

• Wild collection is discouraged — observe without disturbance

XI. Summary

The Guizhou Hillstream Loach is one of the most efficient native algae grazers for hillstream aquaria. It does not jump, does not harass shrimp, and does not require feeding. Its sole task is to remove stubborn biofilm from stone surfaces.

Stock 2–6 individuals in a 40 cm tank or up to 20 in a 60 cm tank. As long as temperature remains low, current strong, and substrate clean, it will remain entirely self-sufficient.

You provide flow and light.
It provides cleanliness.
This is the natural contract of a true hillstream aquarium.